Jerry LeVan <jerry(dot)levan(at)eku(dot)edu> writes:
> I guess the subject says it all, can I install the
> B5 release to a B4 db without starting from scratch?
Afraid not.
When in doubt, the authoritative answer for such questions can be found
by consulting the catversion revision history:
http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h
A mod in this file corresponds to a forced initdb.
regards, tom lane